Core sample retaining means



Nov. 14, 1961 E. J. LYNCH ET AL CORE SAMPLE RETAINING MEANS Filed Jan.20, 1959 INVENTORS% E W. DAVENHALL EUGENfi' J. LYNG'H FIG.4 7

ATTORNEYS l 0 \v I J, 0 2 4 m 2 I Q. F 7 I v a I/(Inl F I. AM m/ F/1114442 7 w 3,008,529 CORE SAIVWLE RETAINING MEAN Eugene J. Lynch,Woodside, N.Y., and Frederick W.

Davenhall, Clarks Summit, Pa., assignors to Acker Drill Company, IncScranton, Pa., a corporation of Pennsylvania Filed Jan. 20, 1959, Ser.No. 787,842 8 Claims. (Cl. 175-243) This invention relates to soilsampling devices and more particularly, to a soil sampling device forcollecting core samples in loose unconsolidated soils.

The main problem of collecting core samples in soils having a fluid orsandy consistency lies in retaining the core sample in conventionalsampling tools.

Heretofore, it has been necessary to use check valves and other similardevices to retain loose or fluid core samples, and in some cases eventhese devices are unable to collect some types of soils. These devicesraise the initial cost of the core sampling tools in which they areused. In addition, they create a maintenance problem as they tend toclog easily and are in need of constant attention.

It is, therefore, an object of this invention to provide a core sampleretaining means for sampling tools, which is capable of retainingsamples of heretofore uncollectable soils. 7 I

Another object of this invention is to provide a core sample retainingmeans which is low in initial cost.

Still another object of this invention is to provide a core sampleretaining means which is readily replaceable and maintenance free.

Still another object of this invention is to provide a core sampleretaining means readily adaptable to various soil sampling tools.

These and other objects of this invention will become apparent from thefollowing specification and drawings. It is to be understood that theembodiment shown in the drawings and hereinafter described is for thepurpose of example only and is not intended to limit the scope of theinvention.

The invention consists, basically, of a flexible generally cylindricaltubular member mounted interiorly of a hollow core sampling tool. Thetubular member is so mounted that it allows the core sample to enter thesampling tool when it is lowered into the soil but does not allow thecore sample to escape from the tool when it is raised to recover thecore sample.

In the drawings:

FIG. 1 is a cross-sectional view of the core sample retaining means incombination with a sampling tool in one phase of a sampling operation.

FIG. 2 is a detailed cross-sectional view of the core sample retainingmeans.

FIG. 3 is similar to FIG. 1 but relates to another phase of a coresampling operation; and

FIG. 4 is a view similar to FIG. 3 showing a fragmentary section of theupper portion of the flexible tubular member collapsed and folded acrossthe tops of the spring fingers to form a barrier.

Referring in detail to the drawings, and more particularly to FIG. 1, atubular core sampling tool is shown. The core sampler comprises an outertubular shell which extends to an intermediate point 14 on the outerlongitudinal dimension of the sampling tool 10 where it abuts with atubular retaining collar 16.

Inside of the outer shell 12 and retaining collar 16 is a core sampleretaining chamber generally indicated at 18 which is defined by atubular inner shell 21 The inner shell 20 is provided with externallythreaded end sections 22. The upper threaded section 22 cooperates withinternal screw threads in the outer shell 12 while '2 the lower section22 cooperates with an internally threaded section in the retainingcollar 16. In this Way, the outer shell 12 and the retaining collar 16are held in positive contact at the point 14. 7

Located interiorly of the retaining collar 16 and extending around theinner circumference thereof, is a mounting ledge 24. The mounting ledge24 is adjacent the lower edge 26 of the inner shell 20 and axiallyspaced therefrom to provide a mount for the core sample retaining meansto be hereinafter described. The mounting ledge 24 extends from theoutside diameter of the inner shell 20 radially inward to a diameterdefining a core sample inlet bore 28 in the lower end of the retainingcollar 16.

' Referring to FIGS. 1 and 2, the core sample retaining device comprisesa hollow cylindrical base member 30 having a relatively'thick lowerportion 32 which is stepped to form a shelf 34. The shelf 34 extendsradially inward to meet an upwardly'extending cylindrical section 36.The inner diameter of the lower section 32 and upper section 36 remainsconstant throughout the axial length of the base member 30 and issubstantially equal to the diameter of core sample inlet bore 28 of thesampling tool 10.

A spring finger core retaining member comprising a constant diameterintermediate portion 38, base flange 40 and a plurality of upwardlyextending spring fingers 42 circumferentially located about theintermediate portion 38 to form a truncated cylindrical section, ismounted on the base member 30. The constant diameter intermediateportion 38 of the spring finger core retaining member is incircumferential juxtaposition with the upwardly extending cylindricalsection 36 of the base mem ber 30, while the base flange 40 of thespring finger core retaining member abuts the shelf 34 on the basemember 30. The spring fingers 42 are of steel or other springy materialand for the size of said sampler will flex about their lower ends butwill not bend so as to be doubled back on themselves and project downinto inlet bore 28.

A flexible generally tubular member 44 open at both ends is mounted withone end on the base member 30 exteriorly of the spring finger coreretaining member by means of a cylindrical retaining collar 46- whichcooperates with the intermediate portion 38 and base flange 40 of thespring finger core retainer and the shelf 34 and upper cylindricalportion of the base member 30 to secure the tubular member 44 and thespring finger core retainer to the base member 30. This combinationcomprises the core sample retaining device.

The upper end of the tubular member 44'comprises a multiplicity offlexible fingers 48 (FIG. 1) which act in combination with the rest ofthe tubular member 44- and the spring fingers 42 of the core retainer toprovide a novel and positive core retaining action.

The core sample retaining device, as described, is mounted on themounting ledge 24 in the retaining collar 16 of the sampling tool 10.The retaining collar 16 is then threaded onto the lower end of the innershell member 20 to positively secure the core sample retaining devicebetween the lower edge 26 of the inner shell 20' and the mounting ledge24 on the retaining ring 16. The sampling tool 10 is now ready to takeand retain a core sample of fluid or unconsolidated soils. 7

Referring to FIG. 1, the motion of the core sampling tool 10 is shown,by the arrow, to be in a downward direction. This direction of motion isused in forcing a core, of the soil to be sampled, up through the coreinlet bore 28 in the retaining collar 16 of the sampling tool 10. As thesampling tool penetrates farther into the soil, the core sample,generally indicated at 50, is forced upwardly through the base member30, spring fingers 42 3 and flexible tubular member 4-4 until the samplechamber 18 is filled.

If the core sample is fluid or of an unconsolidated nature, the springfingers 4-2, above, would be insuflicient to prevent the core sample 50from running back out through the inlet bore 28 and being completelylost when the motion of the sampling tool 19 is reversed to lift thetool and core sample 50 to the surface.

With the plastic tubular member 44 combined with the spring fingers 42,however, the results are altogether different,

Referring to FIG. 3, the arrow shows the direction of motion as havingbeen reversed from that of FIG. 1. After the core sample St) has beenforced into the chamber 18, the flexible bag 44 and the flexible fingers48 thereon are stretched out to their fullest extent as shown in FIG. 1.Upon reversal of motion of the sampling tool 10, the core sample 50, dueto its fluid or unconsolidated state, starts to flow out through thespring fingers 42 and inlet bore 28. The chamber 18, however, beinglonger than the tubular member 44 and the flexible fingers 48 thereon,contains core sample material 50 above the upper end of the tubularmember 44.

The suction created by the escape of part of the core sample 50 causesthe flexible fingers 4S and subsequently the tubular member 44 at itsupper portion thereadjacent the fingers 48 to collapse and bunch andfold itself together and rest on and drape itself across the upper endsof the spring fingers 42 as shown in FIGURES 3 and 4. Thus, the coresample material 54 can no longer flow through the base member 30 of thecore sample retaining means in that the tubular member 44 has collapsedand sealed off the opening therein. The core sample 5% located above theupper end of the tubular member 44 in the chamber 18 is therebyretained.

As can be seen from the above description and drawings our devicesatisfies a long felt need in the core sampling art for retainingsamples of fluid and unconsolidated soils in their authentic,uncontaminated state. Heretofore, this was not possible withconventional sampling tools.

We claim:

1. A core sampling tool comprising, in combination, an inner shelldefining a core retaining chamber, an outer shell surrounding andpartially coextensive with said inner shell, said inner shell having anend section extending below the lower extremity of said outer shell, ahollow retaining collar, having an inlet bore therein communicating withsaid core retaining chamber, fixed to said end section of said innershell and abutting said lower extremity of said outer shell, a mountingledge interior of said retaining collar and spaced apart from the loweredge of said end section of said inner shell, and a core sampleretaining device mounted between said mounting ledge and said lower edgeof said inner shell, said core sample retaining device comprising ringmeans having spring fingers extending into said inner shell coreretaining chamber in spaced relation therewith and a flexible relativelyfrail collapsible tubular member open at both ends and secured at oneend in said ring means and extending between said inner shell and thespring fingers and beyond said fingers on into said core retainingchamber, said ring means with its spring fingers and the flexiblerelatively frail collapsible tubular member freely admitting core samplematerial into said core retaining chamber, said flexible relativelyfrail collapsible tubular member extending beyond said fingers andwithin said inner shell collapsing upon attempted exit of said coresample material that lies generally within the flexible relatively frailcollapsible tubular member beyond said fingers and within said coreretaining chamber and lying over said fingers across the opening formedthereby to form a transverse barrier and seal off said inlet bore andretain said core sample in said retaining chamber.

2. In combination with a core sampling tool havinga core retainingtubular shell device having an inlet bore and a core sample retainingchamber for collecting core samples of unconsolidated soils comprising,a truncated spring finger core retainer mounted in the bore of thesampling tool in spaced relation between the inlet bore sample and thecore retaining chamber thereof, and a flexible relatively frail tubularmember, open at both ends, aflixed at one of its ends to the base ofsaid truncated core retainer and with the other end free to move in saidcore retaining chamber of said sampling tool beyond said truncatedspring finger core retainer an amount so as to collapse and foldgenerally transversely over the ends of said fingers, whereupon when theweight of a collected core sample within the sample retaining chamberand within and above the relatively frail flexible tubular memher onwithdrawing the sampling tool causes the free end of said tubular memberto collapse and engage said spring finger core retainer to seal oil thebore of said sampling tool and prevent the escape of a core sample fromsaid core retaining chamber.

3. The device as described in claim 2 wherein said free end of saidtubular member comprises a plurality of flexible fingers. 1

4. In combination with a core sampling tool, having an inlet bore and acore retaining chamber, a core retaining means in the bore of said toolbetween the inlet bore and the core retaining chamber thereof,comprising a relatively frail flexible tubular member having one fixedend and one free end, both of said ends being open to allow passage ofmaterial through said flexible tubular member, a base member for saidflexible tubular member mounted in the bore of said tool and having abore therein communicating with the bore of said tubular shell, saidfixed end of said flexible tubular member being fixed to said basemember concentric with the bore therein, and said free end of saidtubular member being free to move in the core retaining chamber of saidcore retaining tubular shell, whereupon when the weight of a collectedcore sample within the core retaining chamber and within and above therelatively frail flexible tubular member on withdrawing the samplingtool causes the free end of said flexible tubular member to collapse andin its collapsed condition to seal off the bore in said base member toprevent further escape of said core sample.

5. The device as described in claim 4 wherein said free end of saidflexible tubular member comprises a plurarity of flexible fingers.

-6. A core sample retaining means comprising a hollow elongated basemember having a bore therein and a flexible relatively frail and readilyfoldable open ended tubular member open at each end mounted at one endon said base member circumterentially of said bore therein whereby flowof a material through said bore in one direction is unimpeded and flowof material collected within said bore and beyond said flexible tubularmemher through said bore in the opposite direction causes, when the coresample is withdrawn from taking a sample, said tubular member tocollapse, fold upon itself and seal said bore to prevent further flow insaid opposite direction.

7. A core sample retaining means comprising a hollow elongated basemember having a bore therein, a truncated spring finger core retainingmeans mounted in said base member concentrically within said bore andhaving an aperture therethrough, a flexible double open ended relativelyfrail tubular member having one of its ends mounted concentricallywithin and attached to said base member and surrounding said truncatedcore retaining means, said flexible open ended tubular member having afree end extending beyond the outermost extremity of said truncatedspring finger core retaining means a distance sufficient on collapsingof the tubular member that the tubular member crumples over saidtruncated spring fingers to close off the aperture therethrough, wherebymaterial flowing through said bore and said truncated retaining meanspasses unimpeded through said tubular member and flow of materialcollected within and above the flexible relatively frail tubular memberand above said spring finger core retaining means in the oppositedirection collapses said free end of said tubular member into engagementwith said truncated spring finger retaining means to seal 01f said boreand prevent further flow on Withdrawing the core sample retaining meansfrom taking a core sample.

3. The device as described in claim 7 wherein said free end of saidtubular member comprises a plurality of flexible fingers.

References Cited in the file of this patent UNITED STATES PATENTS OliverMar. 16, 1937 Johnson July 7, 1959 llildebrandt Mar. 8, 1960 FOREIGNPATENTS Sweden Apr. 21, 1938 France Apr. 3, 1955

